Fall Raptor Migration Off to a Strong Start at the Golden Gate

Juvenile Bald Eagle flying by the Golden Gate Bridge
Golden Gate Raptor Observatory volunteers spotted this juvenile Bald Eagle soaring past the Golden Gate Bridge.

© George Eade

August 2017 - On August 14th, the Golden Gate Raptor Observatory began its 35th season of monitoring fall raptor migration at the Marin Headlands, and so far things are off to a promising start. The beginning of the season is often foggy, and this year has been no different; however, raptor counts on clear days have been robust and diverse.

Led mostly by increases in Red-tailed Hawk (Buteo jamaicensis) numbers, both total count to date and raptors per hour (rph, a measure of overall activity) are at 585 sightings and 29.4 rph, which is well above the average of 366 sightings at 20.7 rph. Hawkwatchers have already counted ten species, including Bald Eagle (Haliaeetus leucocephalus), White-tailed Kite (Elanus leucurus), Northern Harrier (Circus cyaneus), and Osprey (Pandion haliaetus). American Kestrel (Falco sparverius) counts are also up.

The number of banded birds is also above normal (47 to date, compared to an average of 31), again driven by Red-tailed Hawks, which have been caught at more than twice the species average for this time of year.

You can find daily updates from the hawk count at www.ggro.org, or by calling the Hawkwatch Hotline at (415) 426-5295.

Last updated: August 31, 2017